1984 gl1200 interestate...carb vaccum

backyardtrouble · May 9, 2012

i have up graded to a 1984 Gl1200,,,,,got a nice bike with extra low miles 28,000, but i am having some carb issues, i have pulled them off, checked everything, set the floats, had to put in a new slow jet, and the carbs were really clean inside, no residue or anything really, but i need to know what is the normal vaccum pull on these carbs...I am getting only 5 across all 4. It is running alot better than before i pulled them but it seems low on the vaccum to me. I Don't know :head bang:

slabghost · May 9, 2012

5 inches vacuum is a good bit actually. I've no idea what is normal. Have you set all the air/fuel mix screws? Have you checked compression?

backyardtrouble · May 10, 2012

..I did check the compression..and they are running at 180 lbs per cylinder, the air cut valve is new, all the diaphrams in the vaccum chambers are like new with no deffects that i can see, the pilot screws are still sealed with the caps, i did not change them due to the fact i did not rebuild the carbs, just inspection, that's when i found the slow jet on NO# 2 bad, so i just ordered a new one and replaced it. Since it is running better at this time, taking the throttle and not smothering down, i guess i wll try it and see how it runs. If pulling 5 is a good vaccum then maybe i am where i need to be since i don't know what they should pull either, but i will appericate more info if everyone thinks this may not be good. Thanks, Paul.

joedrum · May 10, 2012

yes jusr run it awhile with ATF mix in gas.....

AApple · May 10, 2012

I think the location of the vacuum fittings on these things has a lot to do with the amount of measured vacuum.5 inches sounds right to me, considering.
The vacuum advance on my 1100 starts @ a little over 1" of vacuum, and is all in at a little over 3"....that ain't much at all!